Fire crews in the St. John's area had a busy Thursday night.

Around 8 p.m. the department received a report of smoke at Holy Heart Theatre, where Opera on the Avalon was preparing for a performance. 

The building was evacuated while firefighters searched for the source of haze in the main auditorium.

Officials discovered the problem was caused by a burned-out motor on a rooftop ventilation system.

Patrons were sent back into the theatre, and the show was able to begin.  

Meanwhile on Shea Heights, a fire that was burning around the same time destroyed a small cabin in the area of Beaver Pond Road.

A spokesperson for SJRFD said a second, partially-built cabin was damaged.

It is believed the fire was suspicious.